Thermodynamic analysis of products distribution for propane aromatization process

Abstract

The aromatization process of light alkanes is one of the major ways of adding value to the lower saturated hydrocarbons obtained from the refining process and Liquid Petroleum Gas, LPG. The thermodynamic analysis based on Gibbs free energy minimization subject to certain constraints was used to reduce the number of proposed species from thirty-six to thirteen at reaction conditions of 550 °C and 1 bar. The process of minimizing the Gibbs free energy equation was done using MATHCAD and Aspen Plus software in a carbon-free atmosphere. Influence of temperature (400 0C–1000 0C), pressure (1–10 bar), and flow rate (1 M of propane and molar fraction of products) was studied on product distribution in the form of selectivity, yield, and conversion of propane. It was observed that the formation of aromatics was least favored as seen from the yield at various temperatures. The hydrocarbon selectivity and yield were reported on a carbon basis. It was discovered that methane formation was most favored.The temperature which determines the maximum yield of the desired product was determined, yield and selectivity of aromatics were found to be independent of pressure at 1 to 10 bar, and m-xylene was found to be the most favored of the isomers of xylene. This work also presented the computational justification for assuming that isomers of products obtained from propane aromatization are in quasi-equilibrium.

Keywords

• Propane-Aromatization
• Chemical-thermodynamics
• MATHCAD
• AspenPlus
• Carbon-free
• Selectivity